Effectiveness of a direct lift controller(DLC)for in-flight simulation is discussed. A DLC device has been shown to be indispensable for in-flight simulation of backside operating models, hance quick-moving flaps were installed on the variable stability and response airplane(VSRA) of the National Aerospace Laboratory of Japan. After tailoring feedback/feed-forword gains, a model-following system was constructed to simulate backside-operating mother aircraft. Flight verification test results are included and indicate that a DLC is helpful but not required for simulating frontside-operating models, whereas it is mandatory to obtain acceptable model following erreors necessary to simulate backside-operating models. Flight test results for a simulated landing approach in the backside region are also presented.